Was resetting an instance yesterday as most players do; having everyone log off and use an alt to reset the instance. Unfortunately one player decided to log off using alt+f4, keeping his player technically online while appearing offline, so attempting to reset would give an error “Cannot reset, player is still inside the instance”.
At this point we tried again the right way without alt+f4 and this time attempting to reset gave no message at all. A few more attempts with no confirmation message until we just decided to walk in and see if it reset… only to find out we were suddenly locked out of instances for ~30 minutes.
Considering the new 30 instance cap, this is an important issue to resolve.